No, the connections close each time. The users online list based on the IP addresses of the last 15 minutes.

@Philip, does the count also reflect search/spider bots ?!?

Yes

still impressive

Quite

Impressive assuming it's accurate; which I have a hard time believing. The 'old' NTCompatible site never got more than about 100 or so users online, and a LOT more forum posts.
 
Now with the new CMS, we're to believe that the users has increased 10 fold, while the forum posts have decreased?
 
Not saying it's impossible, but unlikely.

The new counter is included in the CMS and counting the visitors of the entire website, not only the message forum.

I disabled the online users feature temporary because of connection problems with the MySQL database server under heavy traffic.

The problem is that MySQL can only run up to 260 simultaneous processes on this server, while the machine had peaks of 1000 Apache processes.
 
This could be a hard limit, but I found nothing in the MySQL sources. Apache had originally also a hard limit of 512 clients, but I recompiled Apache to support 2048 clients.

FYI: You touched on the reason I was directed here earlier: I was looking for the solution to a problem and this site came up along with multiple other ones while going thru Yahoo/Google searches, gotta go with what works, now this site is marked thanks to help from all those knowledgeable.
 
Just because I've been a mainframe programmer for 8+ years doesn't mean I know the inner workings of the PC world (which is why I don't post much here, AT ALL) but I'm definitely learning more everyday now and maybe I won't have to ever go back to them ugly green screens after all (been out of work since November and now moving too so...)!